404 Broken Files

Something in your stack is not working well with remote media, and is either saving the remote URL that WP Offload Media creates back to the Media Library item’s metadata, or doing some on-the-fly URL rewrite during display assuming that it has a path.

I would start by disabling plugins one by one, check to see if it still happens with a newly added Media Library item until the problem stops. I’d start with either of those Cloudflare and WP Rocket plugins.

Other likely candidates are plugins that optimize, crop or otherwise alter media during upload or on display.

You might also want to switch to a stock “Twenty …” theme as it could also be the theme.

-IJ